@Leapingriver  
Who said dragons have any respect in genetics? If they “grow up” from attitude, then “how” they grow up also could be from attitude. It’s possible, but it doesn’t mean it must be that way. We don’t have any data on that, unlike CMC’s Cutie Marks, when we knew they’re gonna get them sooner or later In-Universe.

@NowhereSH  
We see his grown up state in an episode and they don’t just “grow wings”.  
You could argue that since he “grew up fast” they didn’t come in, but do you really think the animators and show writers put that much conscious thought into their decisions? They don’t think “oh animators, make sure not to give Spike wings in his grown up form because he grows up fast so they won’t come in.”  
No, it just doesn’t make sense.

@Maulkin  
Sweetie Belle was celebrating her 5th birthday in “For Whom the Sweetie Belle Toils” and she looked much younger than she normally does and much younger than Twilight looked when she hatched Spike.
 
It’s likely that Twilight was in school before she joined Celestia’s school where she hatched Spike, and it is more of a special secondary school (kinda like Hogwarts, where students start when they’re around 10)

@Background Pony #E98C  
Um… This “school” was Celestia’s School for Gifted Unicorns. Also, in regards of horse aging, watch “For Whom the Sweetie Belle Toils” again.

@Ambris  
More like a sexy freight train, damn.

@Background Pony #8D8B  
@Background Pony #E98C  
These guys get it.
 
@Daneasaur  
You learn something new every day.

Winged spike is a tag, use it.

@Background Pony #E98C  
… CMC didn’t have their cutie marks, that is. Until they were 10-12.

@Maulkin  
But we know Twilight was in school before she was Celestia’s student. She was in Magic Kindergarten. She met those Canterlot friends there in school.
 
And the CMC don’t have their cutie marks and they’re ~10-12.
 
If we assume that ponies age like humans do anyway. Would explain a lot about their inconsistent maturity if they aged more like horses, thus faster, thus everyone is much younger than we assume.

@NowhereSH  
“don’t know nothing”, while that’s technically true it’s also a horrible grammer mistake that completely changes the meaning of the sentence. But at least your mistake made you factually correct.

@Maulkin  
Most theories analyzing the Mane 6s’ ages places them as older teens in human years at the start of the series, as for how many years the series takes place over, I would say two max, using the Gala and what Twi says about a year passing since she came to ponyville in season 4 as cues.

Dragons age by greed, not by year :D  
||i know that didnt make any sense :l ||

Everyone keeps on assuming he’s 6-7 years younger than Twilight, but that doesn’t seem accurate; she started school presumably in Kindergarten, which was likely at age 5. Since Twilight is an adult, and assuming adulthood happens at or around 18, she has probably been an adult at least for a while (seeing how she’s in some sort of college and living on her own when we first see her), so he’s at the very least 13 - probably more, especially since a few years have passed since the start of the series.

@KiltedKey  
I am. I’m not gonna let that get in the way of a clever comment though.

@Leapingriver  

Ah, thank god we have an expert on dragon biology on our side! What with them being fantastical, magical and mythical creatures, I was worried we’d never find someone with solid, tangible facts for us to go by!
 
Next on the list, debating how cutiemarks make no sense because outside of MLP, unicorns and pegasi aren’t known for suddenly gaining magical tattoos on their butts. That’s not how “things” work, afterall.

@Ambris
 
I thought you were straight!

Why a lot of people say Spike don’t obtain wings? I mean, we don’t know nothing about dragons, and we don’t know the past behind Spike to jump for a conclusion.

Adolescence hit Spike like a truck  
A sexy truck

“Grows wings”  
Uh… No. I don’t think that’s how things work…

Oh god, I regret ever commenting about Spike being a baby dragon.

Geez shipping war in here

@Background Pony #13A1  
Why wouldn’t it be? Twilight is a gifted unicorn, so it’s obvious she would start her education pretty early. I like to think she was 7 at the time: it’s early enough and it’s a “magical number” fitting for the element of magic.

@Background Pony #13A1  
I dunno. 9-12?
 
@Background Pony #13A1  
Anything is possible if you think of enough reasons. I just made simplest estimate, it’s not ideal, of course.

@Background Pony #0518  
Considering the CMC have overhauled their treehouse, gone to Canterlot by themselves, and built a booby-trapped parade float, how old do you think they are?
 
@Background Pony #0518  
It’s Princess Celestia’s School for Gifted Unicorns; why would it be required to be like a modern American elementary school instead of Hogwart’s?

@Background Pony #0518  
Oh, sorry. I misinterpreted the post, my bad.  
@RaineV1  
>buck comment  
Ha, called it!
 

So, Twilight was 19 when show started? Eh, no.  
9-10? It’s not Hogwarts, it’s school. 6-7 years is a good estimate for school’s entrance.